Assignments files and examples rework
The main goal of this MR is to remove all manual indexings for the examples showed throughout Assignments. This means deleting all the
File X.Y: Z.tig and their corresponding
Example X.Y: tc --option Z.tig. They are replaced with simple captions (see an example at #29 (closed) or below).
Replace the default squash commit mesage with this summary of all the commits (we don't want 20+ commits, so we squash).
Related to #29 (closed).